1. Field of the Technology
The present invention relates to network equipment location techniques and, more particularly, to a method of sending a location report from target user equipment.
2. Background of the Invention
For Location Service (LCS) of Public Land Mobile Network (PLMN), location estimates of target User Equipment (UE) are obtained through positioning techniques, where UE denotes a UE terminal to be positioned in a PLMN network, and location estimates can be either geographical latitude and longitude information or location of local streets. Location estimates of target UE obtained by PLMN network may be provided to target UE for self positioning, or provided for communication network itself, for zonal charging or operation maintenance, or provided to other client application ends requesting the location of the target UE, such as organizations and individuals, for supplemental service. Therefore, location service is of broad application in terms of emergency assistance, vehicle guidance, intelligence traffic system, work dispatching, team management, mobile yellow page inquiry and network performance enhancement, etc. LCS specifications as well as function mode, structure, state description and message flow of the whole LCS system are illustrated in The 3rd Generation Partnership Project (3GPP).
In PLMN network, function logic entities for implementing location service include Gateway Mobile Location Center (GMLC), user data storage server (HLR/HSS), Central Network (CN) and Radio Access Network (RAN). GMLC may further include Requesting GMLC (R-GMLC), Home GMLC (H-GMLC) and Visited GMLC (V-GMLC). R-GMLC is a GMLC for receiving the location request initiated by LCS client to target UE. H-GMLC is a GMLC which the target UC belongs to, V-GMLC is the current GMLC that is working for target UE, i.e., the GMLC in which the target UE is currently located. R-GMLC, H-GMLC and V-GMLC may be the same physical entity, or be different physical entities. CN may be either a Mobile Switching Center (MSC) or a Serving GPRS Support Node (SGSN).
At present, a change of area event location request is defined in 3GPP specification, and a procedure thereof is also defined. Change of area event location request means that LCS client pre-specifies target area coverage and change of area events, like target UE entering, leaving or sending LCS area event report to LCS client when located in specified area coverage. LCS system transmits information, like the specified target area coverage and change of area event, to target UE. Then target UE stores the information like the specified target area coverage and change of area event, to target UE, and meanwhile starts the corresponding application program. When the application program detects change of area event, like target UE entering, leaving or sending LCS area event report to LCS client when located in specified area coverage, LCS area event report is reported to LCS system, and LCS system will forward this LCS area event report to corresponding LCS client, so as to notify corresponding LCS client that specified change of area event is detected. In addition, LCS client can also appoint target UE to report number of times of LCS area event report, for example, only sending LCS area event report once, or periodically sending in a specified time range. To sum up, by utilizing change of area event location request, LCS client can conveniently define some tracking and monitoring location services, for instance, child tracking, pet tracking and so on, so that location service may be widely applied in the tracking and monitoring field.
FIG. 1 is a message interactive drawing illustrating change of area event location request procedure. As shown in FIG. 1, message interaction of change of area event location request procedure includes the following steps.
Step 101: LCS client sends LCS Service Request to R-GMLC, where the LCS Service Request carries target UE identity, the specified target area coverage and change of area event, and change of area event can be target UE entering, leaving or sending LCS area event report to LCS client when located in specified area coverage. This LCS Service Request can also carry effective time range of LCS Service Request, like start time or end time, as well as number of times that LCS Service Request demands LCS area event report to report. If it is required to send LCS area event report multiply and periodically, this LCS Service Request should further carry time interval for periodically sending LCS area event report. In addition, this LCS Service Request also carries country code of the country that the specified target area coverage belongs to. This LCS Service Request is the above-described change of area event location request.
Step 102: after receiving LCS Service Request, R-GMLC forwards this LCS Service Request to H-GMLC, then H-GMLC checks legality authentication of LCS client, so as to determine whether this LCS Service Request is allowed by target UE to provide location estimate of the target UE for this LCS client. If LCS client is legally authenticated, H-GMLC will send LCS Service Request to the V-GMLC that target UE is located. Otherwise, H-GMLC sends authentication failure acknowledgement to R-GMLC, so as to notify R-GMLC to reject the change of area event location request sent by LCS client in terms of target UE. R-GMLC notifies LCS client that the change of area event location request initiated by this LCS client is rejected, and change of area event location request procedure is ended.
Step 103: after receiving LCS Service Request, the V-GMLC in which target LE is currently located will conform the specified target area coverage carried in this LCS Service Request into terrain identity that can be identified by PLMN network, and send Provide Subscriber Location to the CN in which target LE is currently located, where this Provide Subscriber Location carries target UE identity, specified target area coverage which is transformed into PLMN network geological format as well as change of area event. Corresponding with information carried in LCS Service Request, this target UE request may carry number of times of send LCS area event report. If it is required to send LCS area event report multiply and periodically, this request should carry time interval for periodically sending LCS area event report.
Step 104: the CN in which target UE is currently located detects that target UE is in idle mode, so CN will start paging, authentication and encoding the target UE, so as to check if this target UE is a legal network subscriber. If the target UE is a legal network subscriber, step 105 may be directly executed. Further, the CN in which target UE is currently located sends private check notification, so as to notify target UE there is a LCS client requesting its location estimate. Then target UE personally checks whether to allow LCS system to provide location estimate of this target UE for the LCS client. If the LCS client is verified, target UE will notify CN in which target LE is located of this verification, and then step 105 is executed. If the LCS client is not verified, target UE will notify CN in which target LE is located of this non-verification. Then LCS system will reject the change of area event location request initiated by LCS client in terms of target UE, and end this change of area event location request procedure.
Step 105: the CN in which target LE is currently located sends Location Area Event Invoke request to target UE through RAN, where information carried by this Location Area Event Invoke request is corresponding with that carried by LCS service request. After receiving Location Area Event Invoke, target UE stores the specified target area coverage and change of area event. If this Location Area Event Invoke requires to multiply send LCS area event report, target UE needs to further store the time interval of periodical send LCS area event report. Then target UE starts relevant application program of its own, and monitors occurrence of send LCS area event report.
Step 106: target UE returns Location Area Event Invoke Acknowledgment (Ack) to the CN in which target LE is currently located, so as to notify CN that current change of area event location request has been accepted, and has been processed accordingly.
Steps 107-110: after receiving Location Area Event Invoke Ack, the CN in which. target UE is currently located sends Provide Subscriber Location Ack to the V-GMLC in which target UE is currently located, in order to notify V-GMLC that current change of area event location request has been accepted. After receiving Location Area Event Invoke Ack, the V-GMLC in which target UE is currently located sends LCS Service Response to H-GMLC, so as to notify H-GMLC that current change of area event location request has been accepted. After receiving LCS Service Response, H-GMLC sends LCS Service Response to R-GMLC, so as to notify R-GMLC that current change of area event location request has been accepted. After receiving LCS Service Response, R-GMLC sends LCS Service Response to LCS client; so as to notify request that current change of area event location request has been accepted.
Steps 111 and 112: change of area event of target UE occurs, namely target UE entering, leaving or being located in specified target area coverage, target UE sends LCS area event report to CN through RAN, where CN covers the specified target area coverage, so as to notify CN that change of area event has occurred, namely target UE entering, leaving or being located in specified target area coverage.
Step 113: after receiving LCS area event report, CN that covers the specified target area coverage sends Subscriber Location Report to V-GMLC of the specified target area coverage, so as to notify V-GMLC that the change of area event of target UE has occurred, i.e., that target UE has entered, left or been located in specified target area coverage.
Step 114: after receiving Subscriber Location Report, V-GMLC that covers specified target area coverage sends Subscriber Location Report Ack to CN that covers specified target area coverage, so as to notify CN that location report of target UE has been received, and CN generates a list record for current change of area event location request.
Step 115: after sending Subscriber Location Report Ack to CN that covers specified target area coverage, V-GMLC that covers specified target area coverage sends LCS Service Response to H-GMLC, so as to notify H-GMLC that the change of area event of target UE has occurred, i.e., that target UE has entered, left or been located in specified target area coverage.
Steps 116-118: after receiving LCS Service Response, H-GMLC authenticates LCS client over again, so as to guarantee that LCS client's providing location estimate of this target UE is in authorization scope of this target UE. If LCS client passes authentication of H-GMLC, H-GMLC will send LCS Service Response to R-GMLC, so as to notify R-GMLC that the change of area event of target UE has occurred. After receiving LCS Service Response, R-GMLC sends LCS Service Response to LCS client, so as to notify LCS client that the change of area event of target UE has occurred, i.e., that target UE has entered, left or been located in specified target area coverage.
If time interval of periodic send LCS area event report and number of times of send LCS area event report are carried in change of area event location request, the time interval of send LCS area event report, which is reported to CN that covers the specified target area coverage by target UE, should not be less than the time interval send LCS area event report, which is set in change of area event location request, and total times of send LCS area event report should not exceed the number of times set in change of area event location request, where each procedure of sending LCS area event report is the same as that of steps 111-118 by and large.
At present, in step 102 of change of area event location request procedure defined in 3GPP, after receiving LCS Service Request forwarded by R-GMLC, H-GMLC checks if LCS client is legally authenticated. If LCS client passes the legal authentication, according to country code of the country that specified target area coverage belongs to, where the country code is carried in LCS Service Request, H-GMLC determines whether PLMN network in which target UE is currently located can cover the country where the specified target area coverage is located. If yes, H-GMLC will send LCS Service Request to V-GMLC in which target UE is located according to step 102. Subsequent procedure of change of area event location request is the same as that of above-mentioned steps. If PLMN network in which target UE is currently located cannot cover the country where the specified target area coverage is located, H-GMLC will store the original LCS Service Request forwarded by R-GMLC, then generates a new LCS Service Request, which carries a PLMN network list covering the specified target area coverage, namely all PLMN network identities covering the specified target area coverage. When target UE enters a PLMN network included in this PLMN network list, which is the change of area event, LCS area event report will be reported. Through V-GMLC in which target UE is currently located and CN, H-GMLC downloads the change of area event in this new LCS Service Request as well as all PLMN network lists covering the specified target area coverage to the target UE, so that when target UE enters a PLMN network included in the PLMN network list, LCS area event report will be reported. When entering one or more than one PLMN network included in the PLMN network list, target UE will send LCS area event report to H-GMLC, so as to notify H-GMLC that target UE has entered the PLMN network included in this PLMN network list. After receiving LCS area event report of target UE, H-GMLC will learn that the PLMN network in which target LE is currently located can cover the specified target area coverage already, then through V-GMLC in which target LE is currently located and CN, the H-GMLC will download change of area event in the stored original LCS Service Request as well as the transformed target area coverage that can be recognized by network to target UE, it is requested to send LCS area event report when target UE enters, leaves or is located in specified area coverage.
Because change of area event location request procedure relates to GMLC and CN in which target LE is currently located, also relates GMLC and CN that covers specified target area coverage, GMLC and CN in which target LE is currently located as well as GMLC and CN that covers specified target area coverage must support change of area event location request procedure. However, because of deficiency in terms of implementing function and supporting location service capability, as well as differences among PLMN networks that function entities are located, GMLC that covers specified target area coverage and CN may not support change of area event location request procedure. In addition, according to practical program of service operation, service providers need to develop change of area event location request in a part of area, where function entities like GMLC and CN in certain areas will be updated and rebuilt, while change of area event location request will not be developed in other areas, and function entities like GMLC and CN in these areas will not be updated or rebuilt, so GMLC and CN located in the same PLMN network will have different capabilities for supporting location service. If GMLC and CN that cover specified target area coverage do not support change of area event location request procedure, when target UE enters a PLMN network included in the PLMN network list and the change of area event occurs, the LCS area event report reported by target UE will not be processed, which will lead to failure of processing change of area event location request, and LCS client cannot obtain LCS area event report of target UE, so that procedure exception of change of area event location request will occur. Meanwhile, under this condition, large amount of useless messages will be generated among function entities of PLMN network, so that there will be a waste of PLMN network resource.
From the above description it follows that, after LCS client sends change of area event location request in terms of target UE, if there is any function entity with insufficient supporting capability during procedure of processing the change of area event location request, this procedure thereof will be a failure, and interactive messages among function entities in PLMN network will be useless, consequently leading to waste of PLMN network resource. Especially when target UE requests periodic send LCS area event report, there will be large amount of useless messages in PLMN network, so waste of PLMN network resource will be more prominent. As far as LCS client is concerned, LCS client may have to wait a long time, and receive no corresponding processing result at all, so that execution efficiency of location service is quite low.
To the above-mentioned function entities, processing capability insufficiency toward location service will also lead to direct failure of location services other than change of area event location request.